Micropumps for the controlled and high-precision delivery of insulin are fundamentally known. However, micropumps up to this point are adversely affected by complex manufacturing processes having many nonstandard processing steps. The many special processing steps according to the previous related art make micropumps of this type costly and lower the manufacturing yields.
In addition, known micropumps are not sufficiently precise in regard to the delivered active substance quantities. Micropumps for insulin delivery must operate very precisely at high dosing precision, however, without complex sensors for detecting delivered insulin quantities. An active flow measurement is very problematic in connection with insulin, because the substance reacts to increased temperatures by being damaged, for example, in connection with so-called hot film sensors for flow measurement.
A grave disadvantage of micropumps up to this point is additionally the lack of safety: thus, for example, in micropumps according to the previous related art, the delivered insulin quantity is a function of the pre-pressure in the insulin supply container, which may be placed under mechanical pressure if it is designed as a flexible bag. For example, if the pump wearer of the insulin micropump sits or lies on the supply container, this may result in an unintentional insulin delivery or an unintentional increase of the dose just delivered. In view of the hazard of an insulin overdose, this is to be avoided under all circumstances.
Therefore, an improved micropump for insulin delivery has been developed by the applicant. An application for a patent for this micropump was made with the application DE 10 2008 00 37 92.3, which is not yet published as of the filing date of the present application. The improved micropump is distinguished in that the functional elements of the micropump are exclusively manufactured by structuring from one direction, whereby fragile intermediate states are avoided in the manufacturing of the micropump, so that support films, etc., may in turn be dispensed with during the manufacturing and thus the requirements for large-scale manufacturing of the micropump are provided.
Efforts have been made to optimize micropumps in such a way that they are capable of self-priming and are tolerant of gas bubbles.